Fig. 1

a Electron density (n_e) and c Hall mobility (μ_H) at room temperature as functions of x in ZnSnN_2−xO_x (closed circles). The solid line in a represents the carrier density calculated based on the assumption that the ionization rate of the incorporated oxygen was 30%. The cross marks in c represent the optically derived mobility (μ_opt). Temperature dependence of bn_e and dμ_H; the circles, triangles, inverted triangles, squares, and diamonds represent the values for films with x = 0.055, 0.069, 0.071 0.074, and 0.079, respectively. All the data are included in Additional file 5